Hood for welding molds



y 1933- E. F. BEGTRUP v HOOD FOR WELDING MOLDS Filed April 9, 1932 H l5ATTORNF Patented July 11, 1933 1 v nnwann r. nineteen, or JEnsnY orry,NEW JnnsEY' noon Ion WELDING means Application filed A t-n s,

This invention relates to certain improvements in the welding of railsby s'uperheat' ed molten metal, such as alumino-thermic steel, and hasfor its object to provide a novel {5 and highly efiicient means tobeassociated with the mold to expedite the preheating of the mold and therail ends enclosed therein, said means comprising hood adapted tooverliethe top ofthe mold and being provided 1.- withan imperforatedouble arched top, which will cause the rising combustion products to bedeflected downward against the rail heads and to be vented along thesurfaces of the rail heads, thereby causing the combustion '15 productsto give up much larger proportion of their heat units to the rail headsthan was possible of realization with-the former types of hoods.

The invention is illustrated in the accom- 2 panying drawing, in whichFi 1 is a sectional elevation of a typical rail welding mold adapted foruse without interrupting traflic, the new hood of my invention beingapplied thereto.

Fig. 2 is a perspective view of the hood.

In the alumino-thermic welding of rails,

without interruption to traflic, it is common to employ a three partrefractory mold to enclose the rail ends, including a two part hasesection and a removable cope section, the mold being fashioned toenclose the rail ends which areiseparated from the interior mold wallsby surrounding spaces into which the superheated thermitsteel is pouredso as to surround the rail ends and fuse therewith to form asubstantially uniform weld. The two lower mold sections enclose the railends to substantially the level of the treads or running surfacesthereof andfthe upper or cope section is fitted to and constitutes thecompleting supplement to the lower sections and is separately removableto permit passage of traffic during the preliminaryoperations of placingthe mold and preheating the interior of the mold and rail ends prior tothe actual pouring of the thermit steel. The refractory cope or uppersection is usually pierced by one or more openings leadinginto the moldcavity, such, for example, as the pouring gate and the riser or vent,which 1932/ Serial at. 604,207.:

are usually disposed on opposite sides of the mold, with referenceto therail heads. In order to avoid the necessity, of removing and replacingthe refractory cope to accommo date passing traffic during thepreliminary operations, as aforesaid, it has'beii custommy to apply-tothe top of thelower mold sections a generally dome-like hood which spansthe openings inthe main body of the mold and is intended to retain theproducts of combustion from the blow torch or similar preheating devicein contact with the heads of the rails enclosed within'the mold, thehood being provided with a vcntjopening'in its top to permit the escapeofthe combustion products; This particular type. of hood has beenreasonably effective in preheating the rail ends, but, owing to itsgeneral form and the location ofthe vent in the highest point thereof, avery considerable portion of the hot gases escape through the ventwithout coming into physical contact with the rail ends, so that much ofthe heating effect of these gases is lost. The preheating of the railends in a mold ofthis character and =employing a hood of the formdescribed usually requires about thirtyiminutes, during which time, ifthe traffic is frequent, numerous car wheelswill have passed over thesite of the joint and it is quite evident that the arring and hammeringof the wheels at the joint have a tendency to injure and disintegratethe mold, especially as the latter becomes more frangible as it reachesthe higher temperaturesdesired in the preheating. For these reasons, aswell as that of economy of labor, it is highly desirable that'thenecessary degree of preheat of the rail ends and the interior of themold, prior to the actual pouring of the molten metal, be'accomplishedin the shortest possible time and the instantinvention is designedespecially to meet these. conditions, r Referring to the drawing, 1 and2 indicate the lower sections of the refractory mold adapted to enclosethe ends ofthe rails to be "welded to substantially the level of thetread surface of the rails, the mold sections being provided with theusual cavities defining the space into which the superheated moltenunderstood by those skilled in the art. These cavities extend to the topof the mold sections and define the collar or protuberance, which Icharacterize welds of this type.

As stated, it is customary and, in fact, necessary to preheat the moldand the ends of the rails enclosed therein preparatory to teemingsuperheated molten metal into the mold to'efiect the weld. Thispreheating is effected by means of a blow torch or the like, the flameof which is directed through a preheating gate formed in the lower partof one of the mold sections, such as indicated at 10, and the productsof combustion flowing through the mold cavity, and about the rail endswould quickly escape from the mold, if the latter were not provided witha cope or a hood to confine the combustion products as much as possible.It is inexpedientto use the regular cope during thefpreheatingoperation, because of the labor involved in the frequent removal andreplacement there'- of to accommodate traliic and also because of thelikelihood of damaging the cope or the 'mold by such removals andreplacements.

The ordinary dome-shapedhood with a top vent will obviate the'ClIillCLlltIQS and ob ections incident to the use of the retractorycope, but, as stated, it is more or less waste-- ful of the combustionproducts and, therefore, inefiicient as a means for-preheating the moldand the rail ends, both in the expenditure of time and preheating fuel.The new type of hood embodying my invention, however, avoids all of thenoted objections and provides a means for effecting the necessarypreheating of the rail ends and the interior of the mold in theshortestpossible time.

As shown in the drawing, the hood comprises a hollow metal casting 3having perpendicular end walls 4;, the lower edges of which arefashioned to conform to the upper surfaces of the mold sections 1 and 2and the upper surfaces of the rails, except at points adjacent theheavier portions of the rail heads where the lower edges are cut away toprovide vents 7 immediately adja cent the rail heads. The top and sidesof the hood are formed as double arches 5 and. 6, which are joined inaline substantially above and in general alignment with the heavierportions ofthe rail heads, the lower edges of the sides closely engagingthe top surface of the mold sections. For purposes of convenience inhandling, the hoodis provided with a bail 8 or other suitable handle bymeans of which the hood may be readily applied to and removed fromposition.

As indicated'by the arrows in the drawing,

portions of the rail heads and can escape oniy by way of the vents 7, sothat the said products are kept in contact with the rail heads as longas possible, with the result that hey give upa large amount of theirheat units to'the rail heads, which heat units would have been wasted inthe older type of hood;

While the mold and the hood have been illustrated as of the typeemployed for welding girder or trilby rails, it will be understood thatthe invention is not limited to this particular type, but is equallyapplicable to the welding of ordinary T-rails and rails of any otherstandard pattern, themold sections and the hood being appropriatelyfashioned to cause the products of combustion to be deflected downwardagainstthe rail heads, to circulate thereabout and to be discharged orvented ultimately along the surfaces adjacent the heavier portions ofthe heads.

What I claimis:

1. A hood forwelding molds, comprising end walls having lower marginaledges substantially conforming to the top of the mold and the topsurfaces of the rail heads and having limited sections adjacent thelatter cut-away to provide vents, and a double arched wall forming thesides and top.

2. A hood for welding molds, comprising end'walls having lower marginaledges substantially conforming to the top of the mold and the topsurfaces of the rail heads, and a double arched wall forming the sidesand top.

In testimony whereof I aflin my signature. I

EDWARD FIBE TRUP.

